Manufacture of copper alloys



Sept. 30, 1930. u. DE BERKER ET AL 1,777,192

' MANUFACTURE OF cOPPER ALLOY Fi led March 5, 1930 2 Sheets-Sheet -1 mvv-raes Sept. 30, 1930.: 7 u. DE BERKER Er AL 1,777,192

MANUFACTURE OF COPPER ALLOYS Filed March 5, 1930' 2 Sheets-Sheet 2' LilELONGAT|ON% ELONGATION 7 b TENSILE. STRENGTH TON- PER n W- 6-0 acme/mgovve/v we:

Patented Sept. 30, 1930 UNITED STATES UDO DE BER/KER, WALTER MACHIN, ANDWILLIAM BOUCH OBRIDN GOUDIELOCK, OF

PATENT OFFICE LONDON, ENGLAND, ASSIGNORS TO P-M-G METAL TRUST LIMITED,LONDON, ENG- LAND I MANUFACTURE OF COPPER ALLOYS Application filed March5,1930, Serial No. 433,420, and in Great Britain December 12, 1929.

This invention relates to copper alloys and their production andprovides an improved method of manufacture whereby alloys are producedhaving good casting properties, capable of withstanding high pressures,and which can be readily forged, rolled, extruded, drawn, stamped orotherwise worked.

' This invention forms a further improvement of the co-pendingapplication Serial N0. 377,338, filed July 10, 1929.

It is known (see Ruer and Goerens: Ferrum, 1917, volume 14, page 49, andRuer and Kuschmann, Zeit f. Anorg. Chem. 1927,

volume 164, pages 366-376) that iron and copper do not alloy readilywith one another, and only about 5 per cent of iron can be alloyed withcopper at or about the melting point of copper, and about 20 per cent ofcopper with iron at or about the melting point of iron, and that ifthese limits be exceeded some of the iron (or copper, according to whichmetal predominates) remains. unalloyed when the metals are meltedtogether. In the above-mentioned application, Serial No. 377,338,homogeneous alloys of iron and copper are described containing up to 30per cent of iron, silicon also being included in the alloy. lVe have nowfound that by the addition to a molten mixture of iron and copper of asuflicient quantity of silicon a homogeneous alloy of iron and copper inall proportions of the two metals may be ensured.

For example, two parts of iron have been alloyed with one part of copperby an amount of silicon equal to 10 per cent of the inixture. Equalparts of copper and iron are not completely alloyed by thev admixture of12 per cent=of silicon, but are completely alloyed by incorporating anamount of silicon equal to 18 per cent. Two parts of copper and one partof iron re- I quire an amount of silicon more than 10 per cent, but notmore than 20 per cent of the total mixture to alloy them completely.- Anamount of silicon equal tov about 20 per cent or more of the mixture issuflicient to complete the alloying of iron and copper 111 'anyproportions. But uniformmixtures are obtained when the amount of silicongreatly exceeds 20 per cent, for example, as much as per cent, may beincorporated without separation of the iron from the copper.

We have further. discovered that alloys produced as above described inwhich homogeneousadmixture or alloying of iron and copper 111 Variousproportions isattai'ned can be used with great advantage in theproduction of high grade copper alloys, wherein the homogeneous alloy isan cfli'ective' substitute for tin and other metals as a hardener.

It has been found that by this procedure great savings are effected incost owing to the cheapness of the hardener alloy; at the same time,bronze substitute alloys made by this invention possess better castingpropertles, and fewer foundry waste'rs are produced, while it has beenfound that in service they are more dependable and their performance issuperior to that of the tin V to secure the complete alloying of theiron and copper, and it has also been ascertained that for such purposesthe addition of phosphorus to these alloys is advantageous in that itlowers the melting point of the hardener, increases fluidity and inother ways improves the casting properties of the final alloy with whichthe hardener is incorporated, and that high grade castings can be madedirect from the alloy as first prepared without it being necessary firstto cast the alloy into ingots and remelt, as is commonly necessary withthe high grade alloys.

The invention accordingly consists firstly in the production of alloysof copper and iron in any desired proportion by the use of anappropriate amount of silicon and secondly in the use of such alloyswith or without the addition of phosphorus as hardeners in the formationof high grade copper alloys having properties similar to bronzes,phosphor bronzes, gunmetal and the like.

The composition of the hardener may be varied in accordance with theparticular characteristic which it is desired to give to the finalcopper alloy, but usually it is made with its composition maintainedwithin about the following limits Per cent Iron About 30 to70 CopperAbout to 60 Silicon About 10 to 50 Phosphorus i 0.1 to 10 copper alloys.

In applying the hardener to copper or a copper alloy, the final alloymay conveniently be prepared in a similar manner to that usuallyemployed in the manufacture of copper alloys, such as bronzes, thehardener being melted with the copper, or added when the copper ismelted. a

The hardener above described can be'applied in varying percentages tothe production of copper alloys. For example, in one method of applyingthe hardener, the tin content of admiralty bronze of the approximate.composition 88 per cent copper, 10 per cent tin and 2 per cent zinc, isreplaced by a hardener alloy constituted as above described.

It may also be convenient to vary the composition of the hardeneraccording to the qualities desired in the final alloy.

When it is desired to use the hardener for the manufacture orimprovement of a copper alloy containing in addition elements, otherthan those present in the hardener-,as .described above, theseadditional elements may be introduced into the final alloyindependently, or incorporated in the hardener. For example, in the admiraltybronze substitute alloy, describedabove, the zinc (or a portion thereof)may be incorporated as a constituent of thehardener.

By our invention it is possible to manufacture alloys consistingpredominantly of copper, but incorporating the ingredients iron andsilicon in Widely varying proportions according to the amount andcomposition of A the hardener used. We have ascertained that possessvaluable properties similar to those associated with bronzes and otherhigh grade copper alloys, and that these properties are maintainedsubstantially constant, even though the composition of the alloys may bevaried over a Wide range.

Reference will now be made to the accomremainder being copper. Alloysrepresented by points Within the shaded area bounded by the continuousline A B C D F form a series whose properties have not hitherto beendetermined, but which are now found to be remarkably constant. Thesealloys have good casting properties and possess, in the cast state, veryregular and good mechanical properties which are approximately asfollows Yield point, 811 tons per sq. in. (12.8 to

17.6 kg. mm a Tensile strength, 20-22 tons per sq. in. (32 to 35.2kg./mm

Elongation on 2", 40-20 per cent (50 min.)

The properties of alloys of copper containing iron and silicon changerather suddenly at or near the compositions indicated by the line A B CD E F, in Figure 1, for example 1. When silicon and iron are increasedbeyond the compositions indicated by the position 0 D E of this line,the elongation drops to a low value, usually with a simultaneousdecrease in tensile strength. Figures 2, 3 and 4 represent theelongations and tensile strengths of alloys vcontaining 2.0 per centiron, 6.0 per cent iron, and 3.0 per cent silicon respectively, thesilicon or iron being varied continuously-as indicated; in each seriesof alloys it is shown that the elongation becomes small at or near thecomposition indicated by the line C D E and the tensile strength fallssimultaneously.

2. When the iron content is high and the silicon content low, i. e. withcompositions indicated by points outside the shaded area in theneighbourhood of the point E on the diagram, the iron and copper do notmix readily, homogeneous alloys are not obtained and satisfactorycastings cannot be made.

3. When the iron content is high, but the silicon content low,.i. e. inalloys indicated by points outside the shaded area between the line E Fand the near edge of the diagram, the casting properties are poor,useful castings are difiicult to make, and the alloys have inferiormechanical properties.

4. When the silicon content is high, but.

the iron content is low, i. e. in alloys indicated by points fallingoutside the shaded area between the line B C and the near edge of thediagram, the casting properties are poor, useful castings are diflicultto make, and the alloys have inferior mechanical properties. i

5. When both iron and silicon contents are low, i. e. in alloysindicated by points out. side the shaded area between the line B A F andthe neighbouring edges of the diagram, the alloys possess lower yieldpoints and tensile strengths, but may nevertheless have a commercialusefulness, particularly as alloys for forging, rolling, drawing orotherwise working, as in the manufacture of rods, tubes,

wires, sections and the like.

.the alloy containing The existence of an extensive series ofcommercially useful high grade alloys as defined by the area A B C D E Fin Figure 1 having nearly constant mechanical properties could not beforeseen from the known properties of either silicon-copper orironcopper alloys, nor from the properties of previously known copperalloys containing iron and silicon. These new alloys are easier to castthan either copper-silicon or copper-iron alloys, especiallyby thepreferred 'method described in this specification; on

account of their good casting properties, and their mechanicalroperites, they can be used with advantage or a large variety ofpurposes, for which other copper alloys such as brasses and bronzes havepreviously been used. The alloys can also be worked by ordinarycommercial processes.

For some purposes it is advantageous to incorporate a small amount ofphosphorus, not exceeding 1 per cent, in the above alloys, whereby thecasting properties are somewhat improved. For example. a small amount ofphosphorus. say about 0.1 per cent, may usefully be added to alloys forcastings such as valves. pumps and the like, the mechanical propertiesbeing thereby little aflec ted; or a greater amount may be added, as incastings to be used for bearings, the hardness and strength therebybeing increased. I

As one instance of the commercial usetulness of the alloys, the case maybe cited of 2.0 per cent of iron; 3.0 per cent of silicon; 0.1 per centof phosphorus and the remainder copper. This alloy has excellent castingproperties, and can be used for such purposes as the manufacture ofstrong copper alloy castings; castings to withstand high fluidpressures, such as valves, pumps and bearings. The properties of thealloy are well maintained and it does not oxidize readily at hightemperatures, as in superheating 1 services and the like; it possessesgood resistance to corroslon and to attack by acids, and is suitable forservice under marme condithe like; die castings; high duty tions. It canalso be readily forged, rolled, extruded, drawn, stamped or otherwiseworked, whereby its properties are further improved, and in the Workedcondition can be used for a large variety of purposes, such as strongcopper alloy rods, bolts and nuts, stays, wire, sections, tubes, sheets,drop forgings and stampings, turbine blading and the like wrought forms.It can also be readily welded, as by electric or oxy-acetylene Weldmg.

The proportions given in all the preceding examples are by Weight.

Having now described our invention, what we claim as new and desire tosecure by Letters Patent is 1. A hardener 01' pre-alloy for use in themanufacture of alloys consisging principally of copper, this hardener orp e-alloy containing 30 to 70 per cent of iron,20 to per cent of copperand 10 to 50 per cent of silicon.

2. A hardener or pre-alloy for use in the manufacture of alloysconsisting principally of copper, this hardener or pre-alloy containing30 to 7 0 per cent of iron, 20 to 60 per cent of copper, 10 to 50 percent of silicon and 0.1 to 10 per cent of phosphorus.

3. The process for the manufacture of copper alloys which consists inadding to copper a hardener or pre-alloy containing 30 to per cent ofiron, 20 to 60 per cent of copper and 10 to 50 per cent of silicon.

4. The process for the manufacture of copper alloys which consists inadding to copper a hardener or pre-alloy containing 30 to 70 per cent ofiron, 20 to 60 per cent of copper, 10 to 50 per cent of silicon and 0.1to 1.0 per cent of phosphorus.

5. The process for the manufacture of copper alloys which consists inadding to a copper alloy a hardener orpre-alloy containing 30 to 7 0 percent of iron, 20 to 60 per cent of copper and 10 to 50 per cent ofsilicon.

6. The process for the manufacture of copper alloys which consists inadding to a copper alloy at hardener or pre-alloy containing 30 to 70per cent of iron, 20 to 60 per cent of copper, 10 to 50 per cent ofsilicon and 0.1 to 10 per cent of phosphorus.

7 Alloys consisting of more than 1.5 per cent and less than 5 per centof silicon, "from 0.2 to 11 per cent of iron, the remainder beingcopper.

8. Alloys consisting predominantly of copper and containing also siliconin appreciable amounts up to 5 per cent; iron in appreciable amounts upto 11 per cent; and phosphorus in appreciable amounts up to 1 per cent.

In testimony whereof we have signed our names to this specification. I

UDO DE BERKER.

W. MACHIN. W. B. GOUDIELOCK.

il'u

